Background: coronary artery disease (CAD) is one of the most important causes of mortality around the world. The mortality rate in acute myocardial infarction is about 30%. CAD risk factors change with time and there are very few studies in this field in Iran. These changes may be due to bio-environmental conditions. In this study our objective was to track these changes during a ten years period.

Methods: This study was done in three general hospitals of Tehran University of medical sciences on patients with first acute myocardial infarction (AMI) in years 1371 and 1381. Demographic and specific data were obtained from patient data sheets. Comparison of means was done by t-test and prevalence of risk factors by chi-square test.

Results: Two hundred fifty eight patients in 1371 and 289 patients in 1381 were admitted to three university hospitals due to acute myocardial infarction for the first time. The mean age of women with AMI decreased 4 years (P=0.022). No significant change was seen in other coronary risk factors. We also observed a significant increase in prevalence of myocardial infarction in women with three risk factors (P=0.01).

Conclusion: We found no significant change in the age of male patients and in the CAD risk factors in 1371 and 1381. Mean age of occurrence of AMI in female shows a four-year decrease during this period. More studies are needed to find reasons for this change.